Five die as cave boat sinks

Five tourists were killed yesterday when a boat taking them on a tour of Europe's biggest underground lake turned over and sank in three feet of water.

A party of 33 tourists was in the boat in the Hinterbruehl Seegrotte, near Vienna, when it overturned close to the end of their 45-minute tour. Four Germans and a Belgian woman died.

"We do not yet know what caused the accident but they were just at the end of the trip when [the boat] turned on its own axis and turned over," said a police spokesman. An investigation has begun.

The accident was the first on the lake, which was created by a 1912 mining blast that went dramatically wrong, flooding several galleries of the gypsum mine with an estimated four million gallons of water.

It remained closed until the 1930s, when cavers explored the tunnels and found that there was air as well as water in the huge enclosure. The Seegrotte became an instant tourist attraction.

Its protected position underground, safe from Allied bombing raids, made it attractive to Second World War Nazi military planners. They turned parts of the mine into an underground aircraft factory producing Heinkel HE 162 Salamander jet fighters.

Some of the machinery used to build the planes and a model of one of the jets are still in the tunnels and have been seen by the more than 10 million visitors who have been there since 1945.